The nanoplasmonic impact of chemically
synthesized Au nanoparticles
(Au NPs) on the performance of GaN nanostructure-based ultraviolet
(UV) photodetectors is analyzed. The devices with uniformly distributed
Au NPs on GaN nanostructures (nanoislands and nanoflowers) prominently
respond toward UV illumination (325 nm) in both self-powered as well
as photoconductive modes of operation and have shown fast and stable
time-correlated response with significant enhancement in the performance
parameters. A comprehensive analysis of the device design, laser power,
and bias-dependent responsivity and response time is presented. The
fabricated Au NP/GaN nanoflower-based device yields the highest photoresponsivity
of ∼ 380 mA/W, detectivity of ∼ 1010 jones,
reduced noise equivalent power of ∼ 5.5 × 10–13 W Hz–1/2, quantum efficiency of ∼ 145%,
and fast response/recovery time of ∼40 ms. The report illustrates
the mechanism where light interacts with the chemically synthesized
nanoparticles guided by the surface plasmon to effectively enhance
the device performance. It is observed that the Au NP-stimulated local
surface plasmon resonance effect and reduced channel resistance contribute
to the augmented performance of the devices. Further, the decoration
of low-dimensional Au NPs on GaN nanostructures acts as a detection
enhancer with a fast recovery time and paves the way toward the realization
of energy-efficient optoelectronic device applications.